Parse getting images from server (getDataInBackground not working) - ios

I am new to coding.
Trying to append images from Parse to a [UIImage] but get the error "Cannot convert value of type PFFileObject to expected argument type UIImage.
How can I convert the PFFile to a UIImage?
#Published var profileManageImages = [UIImage]()
ForEach(uploadMedia.profileManageImages, id: \.self) { picture in
Image(picture)
func refreshSideScroll() {
let currentUser = PFUser.current()
let query = PFQuery(className: "Photos")
query.whereKey("uploadedBy", equalTo: currentUser!)
query.limit = 8
query.findObjectsInBackground(block: { (objects: [PFObject]?, error: Error?) in
if error == nil {
for images in objects!{
self.profileManageImages.append(images["image"] as! PFFileObject)
}
}
})
}

You need still to fetch data of image from PFFileObject, like
query.findObjectsInBackground(block: { (objects: [PFObject]?, error: Error?) in
if error == nil, let objects = objects {
for object in objects {
if let file = object["image"] as? PFFileObject {
file.getDataInBackgroundWithBlock{(data: NSData?, error: NSError?) in
if error == nil, let data = data, let image = UIImage(data: data) {
DispatchQueue.main.async {
self.profileManageImages.append(image)
}
}
}
}
}
})

Related

Fetching data from Parse.com into custom cell (swift)

I am attempting to fetch data from parse.com into my custom cell which is full of strings and images. I believe I am either retrieving my PFFile incorrectly from parse.com or I am retrieving the PFFile correctly but converting the file to UIImage improperly. The error i am receiving is going on within the loadData() function. It reads as follows: could not find an overload for 'init' that accepts the supplied arguments
Information
//Used to set custom cell
class Information {
var partyName = ""
var promoterName = ""
var partyCost = ""
var flyerImage: UIImage
var promoterImage: UIImage
init(partyName: String, promoterName: String, partyCost: String, flyerImage: UIImage, promoterImage: UIImage) {
self.partyName = partyName
self.promoterName = promoterName
self.partyCost = partyCost
self.flyerImage = flyerImage
self.promoterImage = promoterImage
}
}
Parse fetch function
func loadData() {
var findDataParse:PFQuery = PFQuery(className: "flyerDataFetch")
findDataParse.findObjectsInBackgroundWithBlock{
(objects: [AnyObject]?, error: NSError?) -> Void in
if (error == nil) {
for object in objects! {
var eventImage0 : UIImage
var eventImage10 : UIImage
let userImageFile = object["partyFlyerImage"] as! PFFile
userImageFile.getDataInBackgroundWithBlock {
(imageData: NSData?, error: NSError?) -> Void in
if error == nil {
let eventImage = UIImage(data:imageData!)
eventImage0 = eventImage!
}
}
let userImageFile1 = object["partyPromoterImage"] as! PFFile
userImageFile1.getDataInBackgroundWithBlock {
(imageData1: NSData?, error1: NSError?) -> Void in
if error1 == nil {
let eventImage1 = UIImage(data:imageData1!)
eventImage10 = eventImage1!
}
}
//Error below
var party1 = Information(partyName: (object["partyName"] as? String)!, promoterName: (object["partyPromoterName"] as? String)!,partyCost: (object["partyCost"] as? String)!, flyerImage: UIImage(data: eventImage0)!, promoterImage: UIImage(data: eventImage10)!)
self.arrayOfParties.append(party1)
}
}
self.tableView.reloadData()
}
}
You are fetching data from Parse in background, but processing on main thread. Try this:
func loadData() {
var findDataParse:PFQuery = PFQuery(className: "flyerDataFetch")
findDataParse.findObjectsInBackgroundWithBlock{
(objects: [AnyObject]?, error: NSError?) -> Void in
if (error == nil) {
for object in objects! {
var eventImage0 : UIImage
var eventImage10 : UIImage
let userImageFile = object["partyFlyerImage"] as! PFFile
userImageFile.getDataInBackgroundWithBlock {
(imageData: NSData?, error: NSError?) -> Void in
if error == nil {
let eventImage = UIImage(data:imageData!)
eventImage0 = eventImage!
let userImageFile1 = object["partyPromoterImage"] as! PFFile
userImageFile1.getDataInBackgroundWithBlock {
(imageData1: NSData?, error1: NSError?) -> Void in
if error1 == nil {
let eventImage1 = UIImage(data:imageData1!)
eventImage10 = eventImage1!
var party1 = Information(partyName: (object["partyName"] as? String)!, promoterName: (object["partyPromoterName"] as? String)!, partyCost: (object["partyCost"] as? String)!, flyerImage: UIImage(data: eventImage0)!, promoterImage: UIImage(data: eventImage10)!)
self.arrayOfParties.append(party1)
}
}
}
}
}
}
self.tableView.reloadData()
}
}
Your fetching your images Asynchronously and creating your Information cell Synchronously. So when you create the cell, the images are likely not loaded and your are in effect sending nil to the constructor for the cell.
In the following code you are retrieving the image data async:
userImageFile.getDataInBackgroundWithBlock {
(imageData: NSData?, error: NSError?) -> Void in
if error == nil {
let eventImage = UIImage(data:imageData!)
eventImage0 = eventImage!
}
}
So when you assign the image data to eventImage0, the call to the Information cell initializer has probably already happened.
You need to modify the code to instead of passing the image into the cell view initializer, allow you to access the UIImageview from the Information cell, so that when the background image loads complete you can simply set the loaded image into that UI/PF/ImageView.

How to sort Object Array from a PFQuery?

Hi I have a PFQuery where I am retrieving map images and I need to sort them so that i can retrieve the correct image in my code. This is currently my code:
func retrieveImages() {
self.imageArray = [UIImage]()
var query = PFQuery(className:"Maps")
query.orderByDescending("createdAt")
query.findObjectsInBackgroundWithBlock {
(objects: [AnyObject]?, error: NSError?) -> Void in
if error == nil {
if let objects = objects as? [PFObject] {
for object in objects {
self.objectNames.append(object["Name"]!)
let userImageFile = object["imageFile"] as! PFFile
userImageFile.getDataInBackgroundWithBlock {
(imageData: NSData?, error: NSError?) -> Void in
if error == nil {
if imageData != nil {
let imageData = imageData
var image = UIImage(data:imageData!)
if image != nil {
self.imageArray.append(image!)
}
}
}
}
}
}
}
}
}
I tried to sort the query by using the orderByDescending function but when i run the code only the names of the objects are sorted and the images themselves are not. There also seems to be no pattern in how the images are sorted because each time I run this code the order of the images are different. Any advice or insight would be appreciated.

Fatal error when trying to load images from parse using Swift

I am getting a fatal error: unexpectedly found nil while unwrapping an optional value. I get this error after the code gets to self.imageArray.append(image!) from this code:
func retrieveImages()
{
var query = PFQuery(className: "Maps")
query.findObjectsInBackgroundWithBlock {
(objects: [AnyObject]?, error: NSError?) -> Void in
if error == nil && objects != nil {
let objects = objects as! [PFObject]
for object in objects {
let imageFile = object["imageFile"] as! PFFile
imageFile.getDataInBackgroundWithBlock {
(imageData: NSData?, error: NSError?) -> Void in
if error == nil {
if imageData != nil {
let imageData:NSData! = imageData
let image = UIImage(data: imageData)
self.imageArray.append(image!)
}
}
}
}
}
}
}
I have checked each line of code and image does not become nil until i try to append it to the end of the imageArray.
like previous mentioned, you are reassigning a lot of variables. Try you if-let statements on the optional variables like this:
func retrieveImages(){
var query = PFQuery(className: "Maps")
query.findObjectsInBackgroundWithBlock { (objects: [AnyObject]?, error: NSError?) in
if let objects = objects as? [PFObject] where error == nil {
for object in objects {
if let imageFile = object["imageFile"] as? PFFile {
imageFile.getDataInBackgroundWithBlock { (imageData: NSData?, error: NSError?) in
if let imageData = imageData, let image = UIImage(data: imageData) {
self.imageArray.append(image)
}
}
}
}
}
}
}

Problems When Trying to display images from Parse using Swift

I am trying to display an image from parse using swift. This is my code:
var query = PFQuery(className: "Maps")
query.getObjectInBackgroundWithId("1234asdf3456") {
(object: PFObject?, error: NSError?) -> Void in
if error == nil
{
println(object)
var objectAsPF = object as PFObject!
let file = objectAsPF["imageFile"] as! PFFile
file.getDataInBackgroundWithBlock {
(imageData:NSData?, error:NSError?) -> Void in
if error == nil {
if let imageData = imageData {
let map:UIImage = UIImage(data: imageData)!
self.MapView.image = map
println("success")
}
}
}
}
else
{
println(error)
}
}
I set a breakpoint at println("success") and i checked the variable values and everything is fine until i try to convert imageData to UIImage. Any tips?
Use this code to retrieve images from parse then convert it from a PFFile to a UIImage...
var query = PFQuery(className:"Maps")
query.findObjectsInBackgroundWithBlock {
(objects: [AnyObject]?, error: NSError?) -> Void in
if error == nil {
// The find succeeded.
self.scored = objects!.count
// Do something with the found objects
if let objects = objects as? [PFObject] {
for object in objects {
let userImageFile = object["imageFile"] as! PFFile
userImageFile.getDataInBackgroundWithBlock {
(imageData: NSData?, error: NSError?) -> Void in
if error == nil {
if let imageData = imageData {
let image = UIImage(data:imageData)
if image != nil {
self.imageArray.append(image!)
}
}
}
}
}
}
} else {
// Log details of the failure
println("Error: \(error!) \(error!.userInfo!)")
}
dispatch_async(dispatch_get_main_queue()) {
println("Finished Loading Image")
}

Updating Objects in iOS Swift with Parse

I've a table 'preferences' where user preferences are saved along with username. I created this method to update current user's preference' but somehow it doesn't seem to work. I am not sure if the portion "prefQuery.getObjectInBackgroundWithId(object.objectId)" is required at all.
I am new to Parse, could somebody please help me point what could be the issue.
func userPreferences(){
var currUser = PFUser.currentUser()
var prefQuery = PFQuery(className: "preferences")
var prefObj = PFObject(className: "preferences")
if let currUserName = PFUser.currentUser()?.username {
prefQuery.whereKey("username", equalTo: currUserName)
}
prefQuery.findObjectsInBackgroundWithBlock {
(objects: [AnyObject]?, error: NSError?) -> Void in
if error == nil {
if let objects = objects as? [PFObject] {
for object in objects {
prefQuery.getObjectInBackgroundWithId(object.objectId){
(object: PFObject?, error: NSError?) -> Void in
if error == nil || object != nil {
prefObj["agestart"] = self.fromAge.text
prefObj["ageend"] = self.toAge.text
prefObj["location"] = self.location.text
ProgressHUD.showSuccess("Update successful")
} else {
ProgressHUD.showError("Update failed")
}
}
}
}
}
}
}
I found the issue and have updated my codes. The working codes are below; the issue was with the "prefObj["agestart"]" block of codes where I was using the wrong Query instance. You can compare the two snippets:
func userPreferences(){
var currUser = PFUser.currentUser()
var prefQuery = PFQuery(className: "preferences")
var prefObj = PFObject(className: "preferences")
if let currUserName = PFUser.currentUser()?.username {
prefQuery.whereKey("username", equalTo: currUserName)
}
prefQuery.findObjectsInBackgroundWithBlock {
(objects: [AnyObject]?, error: NSError?) -> Void in
if error == nil {
if let objects = objects as? [PFObject] {
for object in objects {
prefQuery.getObjectInBackgroundWithId(object.objectId){
(prefObj: PFObject?, error: NSError?) -> Void in
if error != nil {
println(error)
ProgressHUD.showSuccess("Error while updating")
} else if let prefObj = prefObj {
prefObj["agestart"] = self.fromAge.text
prefObj["ageend"] = self.toAge.text
prefObj["location"] = self.location.text
ProgressHUD.showSuccess("Update successful")
prefObj.saveInBackgroundWithBlock({ (Bool, error: NSError!) -> Void in })
}
}
}
}
}
}
}
The best way to cut your code to the maximum, you can see below:
func userPreferences() {
let prefQuery = PFQuery(className: "preferences")
if let currUserName = PFUser.current()?.username {
prefQuery.whereKey("username", equalTo: currUserName)
}
prefQuery.findObjectsInBackground {
(objects, error) in
if error == nil {
if let objects = objects {
for object in objects {
object["agestart"] = "ur value"
object["ageend"] = "ur value"
object["location"] = "ur value"
print("Update successful")
object.saveInBackground()
}
}
}
}
}

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